## Angles in A Line

(Point, Line, Segment, Ray, Plane and Space Concepts)

Dot; It is an undefined term. The trace left by the pointed tip of the pen on the paper gives an idea about the point. The point has no size. The points are named with capital letters. The set of all points is called space.

True; It is a set of points. Lines are called “line d”, “line k”. A line has at least two different points. If more than two points are taken on a line, these points are called linear points.

Line piece; The set of all points between different points of a line, such as A and B, is called the segment AB and denoted by [AB].

Ray; The geometric term that starts from a point of a line and can be extended straight in one direction and has no thickness and no length.

Plane; Its length and width is taken as a geometric term that can be expanded straight and unlimitedly but has no thickness. The parallelogram region model is used as a plane.

**ANGLES**

Pain; The combination of two rays with common starting points is called the sides of the angle, and the common point of the rays is called the corner of the angle.

The measure of the central angle that sees an arc that is 1/360 of the circumference of a circle is called 1 degree. 1/60 of a degree is called 1 minute, and 1/60 of a minute is called 1 second.

Angles with equal dimensions are called equilateral angles.

Two angles whose dimensions are 180 ° in total are called complementary angles, and two angles whose dimensions total 90 ° are called complementary angles.

If one of the angles formed by two intersecting lines is 90 °, these lines are perpendicular to each other.

Angles with common corners and sides with opposite rays are called opposite angles.